Write Context Parameters to Database - Talend Administrative Console - talend

Does anyone know how to write context parameter values directly to the talend db?

The component tContextDump creates a data flow of your context, where each row is a key/value pair. You can write that data flow anywhere you want, for example to a database, using any of the tDBOutput components. To load your job's context from such a database table (or from any other source), you can use tContextLoad in your job, or you can use the "implicit context load" feature, either at the job level or at the project level. It allows your jobs to get their context parameters from another source, rather than the default property file mechanism.
Not sure what you mean by "the talend db" in your question. The Talend Administration Center (TAC) does have a DB of its own, and if you use Talend's scheduling capabilities, then you will be able to store context values for your job as well, which will override anything that you put into your job in the studio. These context values would then be stored in "the talend db", but this doesn't have anything to do with the discussion above.

You can use context.put(key,value) to put value in context and context.get(key) to get the value anywhere in a job.

Related

ADF - what's the best way to execute one from a list of Data Flow activities based on a condition

I have 20 file formats and 1 Data Flow activity that maps to each one of them. Based on the file name, I know which data flow activity to execute. Is the only way to handle this through a "Switch" activity? Is there another way? e.g. can I parameterize the data flow to execute by a variable name?:
Unfortunately , there is no option to run one out of list of dataflows based on input condition.
To perform data migration and transformation for multiple tables, you can use same dataflow and parameterize the dataflow by providing the table names either during the runtime or use a control table to hold all the tablenames and inside foreach , call the dataflow activity. In the sink settings, use merge schema option.

Best practices for Informatica Webservice workflow

I have created a Informatica webservice workflow which takes 1 parameter as input. A Webservice provider source definition is used for this and mapping is a one-way type.
Workflow works fine when parameter is being passed. But when the same workflow is triggered from Informatica Power center directly (in which case no parameters are passed), mapping that contains webservice provider source definition takes 3 minutes to complete (Gives Timeout based commit point in the log).
Is it a good practice to run the webservice workflow from power center directly? And is there a way to improve its performance when triggered from power center directly?
Note: I am trying to use 1 workflow for both - 1) Pass the parameter from web 2) Schedule the workflow in Informatica
Answers to your questions below.
Is it a good practice to run the webservice workflow from power center directly?
Of course it depends on requirement - whether you need to extract data automatically from WS or not. If you pass parameter using some session then i dont see much issue here and your session is completing within time.
So, you can create a new session/command task/shell script to create a param file and then use it in original session so it is passed on to WS.
In a complex scenario, you may have to pass multiple values, in such case, i would recommend to use a parent workflow to call original workflow multiple times and change param every time before call.
Is there a way to improve its performance when triggered from power center directly?
It is really depends on few factors.
The web service - Make sure you are using correct input and output columns. Most of the time WS are sensitive to outside call and you need to choose optimized column to extract data for better performance. You can work with WS admin to know correct column.
If informatica flow is complex then depending on bottle neck transformation/s (source, target, expression, lookup, aggregator, sorter), we can check and take actions.
For lookup, you can add new filter to exclude unwanted data, remove unwanted columns etc.
For aggregator, you can use sorter before to improve perf.
... like this

Best practices for parameterizing load of multiple CSV files in Data Factory

I am experimenting with Azure Data Factory to replace some other data-load solutions we currently have, and I'm struggling with finding the best way to organize and parameterize the pipelines to provide the scalability we need.
Our typical pattern is that we build an integration for a particular Platform. This "integration" is essentially the mapping and transform of fields from their data files (CSVs) into our Stage1 SQL database, and by the time the data lands in there, the data types should be set properly and the indexes set.
Within each Platform, we have Customers. Each Customer has their own set of data files that get processed in that Customer context -- within the scope of a Platform, all Customer files follow the same schema (or close to it), but they all get sent to us separately. If you looked at our incoming file store, it might look like (simplified, there are 20-30 source datasets per customer depending on platform):
Platform
Customer A
Employees.csv
PayPeriods.csv
etc
Customer B
Employees.csv
PayPeriods.csv
etc
Each customer lands in their own SQL schema. So after processing the above, I should have CustomerA.Employees and CustomerB.Employees tables. (This allows a little bit of schema drift between customers, which does happen on some platforms. We handle it later in our stage 2 ETL process.)
What I'm trying to figure out is:
What is the best way to setup ADF so I can effectively manage one set of mappings per platform, and automatically accommodate any new customers we add to that platform without having to change the pipeline/flow?
My current thinking is to have one pipeline per platform, and one dataflow per file per platform. The pipeline has a variable, "schemaname", which is set using the path of the file that triggered it (e.g. "CustomerA"). Then, depending on file name, there is a branching conditional that will fire the right dataflow. E.g. if it's "employees.csv" it runs one dataflow, if it's "payperiods.csv" it loads a different dataflow. Also, they'd all be using the same generic target sink datasource, the table name being parameterized and those parameters being set in the pipeline using the schema variable and the filename from the conditional branch.
Are there any pitfalls to setting it up this way? Am I thinking about this correctly?
This sounds solid. Just be aware that you if you define column-specific mappings with expressions that expect those columns to be present, you may have data flow execution failures if those columns are not present in your customer source files.
The ways to protect against that in ADF Data Flow is to use column patterns. This will allow you to define mappings that are generic and more flexible.

Talend : how to change context variables for all jobs?

I am now working on Talend Open Studio. I have many jobs.
I need to modify the content of my unique context repository, for instance, to add a new context variable. thus, i wish to spread this new context variable in all the jobs I have.
For now, I had to open each job and manually to add manually the context variable I want to spread into the jobs:
Is there a way to directly spread a context variable in all my jobs from the context repository I have modified ?
This is a bug even I have come across. On some occasions, just updating and saving the context groups propagates the updates across all the jobs using that context group. At some other times, it does not.
As per the link below, Shong from Talend team says that this is supposed to be manual as not all context variables are needed in all jobs. However, I personally feel, this should be the other way round. Whatever is not needed should be manually removed, else all updates should be reflected in all jobs.
https://www.talendforge.org/forum/viewtopic.php?id=19199

How to force an empty output file with Azure Stream Analytics

I have configured a Stream Analytics Jobs so that input data goes to an Azure Data Lake repository every hour.
Sometimes there is no event to track, so no output. But my Data Factory goes in error because the file doesn't exist.
I wonder if exist a way to force empty file out from Stream Analytics?
Many thanks!
You can look at our common query patterns here. In particular I think you can use the one named "fill missing values" to generate some events regularly, even when there is no input.
Let me know if it works for you.
Thanks!
JS
Are you using ADF v2?
I didn't find anything inbuilt in ADF to come up with it.
But I can see few workarounds - starting from simplest one:
In your ASA query, you can use WITH statement and union your input with a fake empty message. - Then there will be always output
As a second output in ASA job you can store in some DB info whenever a file was produced. Then in ADF you can check whenever there are files and run copy conditionally.
In ADF run web activity e.g. LogicApp/FunctionApp to get info whenever files in container exist.
Find the way to do it...
I had an activity using the data lake analytics, what I do is to run an U-SQL than read data with no transformation and write it to the output with headers.
In that way the activity always write an output file!
Very easy!